Locking device for switch case components



June 4, 1968 A. A. DI PlLLA LOCKING DEVICE FOR SWITCH CASE COMPONENTS Filed Dec. 1, 1965 ATTORNEY United States Patent 3,387,107 1 LOCKING DEVICE FOR SWITCH CASE COMPONENTS Anthony A. Di Pilla, Philadelphia, Pa., assignor to Robertshaw Controls Company, Richmond, Va., a corporation of Delaware Filed Dec. 1, 1965, Ser. No. 510,769 6 Claims. (Cl. 200-168) This invention relates to switch case components and in particular to locking means for assembling switch case components.

In attaching a pair of switch case components to each other, it is desirable that the components may also be easily separated to facilitate repair or replacement of one of the components. Such an assembly is best attained by means of resilient clamping means, however, the inherent nature of such resilient clamping means presents additional problems such as accidental disengagement and faulty switching operations.

It is therefore, an object of the present invention to preclude accidental disengagement between assembled switch case components.

Another object of the present invention is to lock the clamping means which retain a pair of switch case components in assembled relationship.

The present invention has another object in that mating surfaces of adjacent switch case components are maintained in contact with each other by clamping and locking means.

In accordance with a preferred embodiment, the present invention includes a pair of switch case components adapted to be connected as a unitary assembly, bracket means on one of the components, clamping means on the other of the components engaging the bracket means to connect the pair of components to each other, and locking means engaging the bracket and clamping means to lock the same whereby the pair of components are retained in their connected relationship to each other.

Other objects and advantages of the present invention will become apparent from the following description of a preferred embodiment taken in connection with the accompanying drawings wherein:

FIG. 1 is an exploded perspective view of an illuminated push button switch assembly embodying the present invention;

FIG. 2 is a partial elevation view on an enlarged scale of assembled lower parts of FIG. 1; and

FIG. 3 is a cross-section taken along line 33 of FIG. 2.

With reference to FIG. 1 of the drawing, a switch case assembly embodying the present invention includes a pair of switch components to be assembled as a unitary device. One such component is a switch unit, indicated generally at 10, which includes any suitable type of electric switching mechanism with a suitable actuator 12 and electric leads 14. An inverted U-shaped bracket has opposed legs 16 secured to the switch casing as by rivets 18 and a bight portion plate 20 with a centrally disposed aperture 22.

The other component of the switch case assembly includes an actuator unit indicated generally at 24, having an opened top housing 26 that receives a combined push button and lamp mounting 28 from which an actuating plunger 30 depends. The lower part of housing 26 is defined by opposed extensions 32 and 34 of the housing side walls, which terminate in inwardly transverse ends 36 and 38, respectively, for attachment to a retaining clamp means. Such retaining clamp means includes a flat plate 40, centrally apertured at 41, having a rigid leg 42 centrally extending perpendicularly downwardly from one edge and terminating in an inwardly "ice bent hook portion 44. An opposite edge of plate 40 has a pair of resilient legs 46 and 48 extending perpendicularly downwardly and terminating in resilient lugs 50 and 52, respectively; as is apparent in FIG. 1, the resilient legs 46 and 48 are spaced from each other an equal distance from the centerline of the plate 40 to define a central mounting space therebetween.

The retaining clamp means includes a second fiat plate 54, centrally apertured at 55 and bent upwardly on its opposite ends to define offset mounting ears 56 and 58 for attachment to the housing 26 and the retaining clamp plate 40. The end 36 of housing side wall 32 is sand wiched between the end portion of clamping plate 40 and the offset ear 56; the three elements are securely fastened together as by rivets 60. Similarly, the end 38 of housing side wall 34 is sandwiched between the other end portion of clamping plate 40 and the offset ear 58 and fastened by rivets 62.

Adjacent its edge on the side with the resilient legs 46 and 48, the flat plate 54 is provided with an upwardly disposed stop tab 64 that may be integrally'formed as a projection on the plate 54 or may merely be a deformed cut out from the plate 54. As is illustrated in FIG. 3, the stop tab 64 is defined by a pair of adjoining cam surfaces 66 and 68 with different slopes. The stop tab 64 is located in a plane centrally between the resilient legs 46 and 48 (FIG. 1).

The switch unit 10 is attached to the actuator unit 24 by slantingly inserting one edge of bracket bight portion 20 under the rigid hook 44 and then pushing the unit 24 upwardly so that the other edge of bracket bight portion 20 effects reciprocation of the resilient lugs 50 and 52. Thus, the switch unit 10 may be easily and rapidly snapped into place with actuator unit 24. When so assembled, the flat plate 54 and the bracket bight portion 20 are maintained in surface contact with each other throughout their mating areas, and the free end of actuating plunger 30 extends through the aligned apertures 41, 55 and 22 for cooperation with the switch actuator 12 as by depression of the biased push button 28. The bracket aperture 22 is larger than the other aperture in order to provide sufiicient clearance for the free end of actuating plunger 30 during the assembly operation.

The switch unit 10 and actuator 24 are retained in their assembled relationship by means of a resilient locking clip 70 which has a generally elongated C-shaped configuration defined by spaced arms 72 and 74 normally biased toward each other. The arm 74 has a centrally located rectangular slot 76 and terminates in an upwardly curved end 78. As is illustrated in FIG. 3, the locking clip 70 is inserted between the clamps resilient legs 46 and 48 with the arm 72 engaging the undersurface of the bracket bight portion 20. Such insertion is facilitated by the curved end 78 which rides up the'stop tab cam 66; thus, the resiliency of the clip 70 permits it to be snapped into a locked position when the arm slot 76 receives the stop tab 64.

Since the clamping plate leg 42 is rigid,'the opposite clamping means, i.e., the legs 46 and 48 must be resilient to permit assembly. Thus, without the clip 70, any undue vibration would effect separation between the mating surfaces of the plate 54 and bight portion 20 and cause deflection outwardly (FIG. 3) of the resilient legs 46 and 48. In addition to the unfavorable effects on the switching mechanism itself, such separating and deflecting movements could result in the switch unit 10 being disengaged from the actuator unit 24. However, in accordance with the present invention, the locking clip 70 maintains the plate 54 and bight portion 20 in surface contact and prevents the resilient legs 46 and 48 from flexing.

The stop tab 64 retains the locking clip 70 in place until disassembly is desired. Because of the lesser slope of cam surface 68, the forward edge of arm slot 76 will easily ride thereon when an outward force (FIG. 3) is applied to the locking clip 70 for disassembly purposes. As is apparent from FIGS. 1 and 3, the side edges of the arm slot 76 are closely adjacent the side edges of the stop tab 64 whereby the locking clip 70 is prevented from rotation. Rotation of the locking clip 70, and in turn the switch unit 10, is further precluded by the location of the stop tab 64 which fixes the bight end of clip 70 between the resilient legs 46 and 48.

Inasmuch as the preferred embodiment of the present invention is subject to many modifications and changes in details, it is intended that all matter contained in the above description or shown on the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In a switch case assembly, the combination comprising a pair of switch case components adapted to be connected as a unitary assembly,

bracket means on one of said components,

clamping means on the other of said components engaging said bracket means to retain and connect said pair of components to each other,

said clamping means including first and second plates,

said first plate having rigid leg means on one edge and resilient leg means on another edge, said rigid and resilient leg means extending beyond said second plate to engage said bracket means whereby the same is resiliently retained in engagement with said second plate, and

a resilient clip resiliently locking said bracket means to said second plate whereby said pair of components are locked in their connected relationship to each other.

2. The combination as recited in claim 1 wherein said resilient leg means comprises a pair of spaced leg members and said resilient clip is disposed between said leg members.

3. The combination as recited in claim 2 wherein said second plate has a stop tab thereon and said resilient clip has slot means receiving said stop tab to dispose and retain said resilient clip in a proper locking position.

4. The combination as recited in claim 3 wherein said resilient clip has a curved end portion and said stop tab has cam means engageable by said curved end portion to facilitate assembly of said resilient clip.

5. The combination as recited in claim 1 wherein the other of said components includes an actuating plunger and wherein said first plate, second plate and bracket means have aligned apertures through which said plunger reciprocably extends to effect actuation of the one of said components.

6. The combination as recited in claim 5 wherein the one of said components comprises a switch mechanism and said bracket means comprises an inverted U-shaped bracket having leg portions attached to said switch mechanism.

References Cited UNITED STATES PATENTS 2,003,856 6/1935 Gimbel 24259 2,208,325 7/1940 Krutsch 28790 2,474,959 7/1949 Rieves 287-90 3,090,949 5/1963 Hallerberg 200159 3,143,214 8/1964 Moore et al 24-23 ROBERT K. SCI-IAEFER, Primary Examiner.

H. O. JONES, Assistant Examiner. 

1. IN A SWITCH CASE ASSEMBLY, THE COMBINATION COMPRISING A PAIR OF SWITCH CASE COMPONENTS ADAPTED TO BE CONNECTED AS A UNITARY ASSEMBLY, BRACKET MEANS ON ONE OF SAID COMPONENTS, CLAMPING MEANS ON THE OTHER OF SAID COMPONENTS ENGAGING SAID BRACKET MEANS TO RETAIN AND CONNECT SAID PAIR OF COMPONENTS TO EACH OTHER, SAID CLAMPING MEANS INCLUDING FIRST AND SECOND PLATES, SAID FIRST PLATE HAVING RIGID LEG MEANS ON ONE EDGE AND RESILIENT LEG MEANS ON ANOTHER EDGE, SAID RIGID AND RESILIENT LEG MEANS EXTENDING BEYOND SAID SECOND PLATE TO ENGAGE SAID BRACKET MEANS WHEREBY THE SAME IS RESILIENTLY RETAINED IN ENGAGEMENT WITH SAID SECOND PLATE, AND A RESILIENT CLIP RESILIENTLY LOCKING SAID BRACKET MEANS TO SAID SECOND PLATE WHEREBY SAID PAIR OF COMPONENTS ARE LOCKED IN THEIR CONNECTED RELATIONSHIP TO EACH OTHER. 